The present invention relates to a photovoltaic device.
This device type is widely used and its purpose is to convert solar energy to electrical energy.
To do that, these devices are provided with photovoltaic cells which will be illuminated by sunlight and convert this light into electrical energy by a photoelectric effect.
In order to improve the yield of this type of device, the use of concentrated light is known; this also has the advantage of reducing the consumption of primary photovoltaic material. To this end, the cells can be coupled to a light guide provided for receiving the photons and for better guiding them to the surface of the photovoltaic cells.
In some of these devices, the cells are arranged on a reflector configured for reflecting photons and allow their recapture by the waveguide. The waveguide is then arranged in contact with this reflector.
However, it was observed that devices of this type had some disadvantages. In fact, the reflectors have a coefficient of reflection that is not ideal and this results in losses on each reflection. Additionally, each reflector generally has local roughnesses, for example because of the roughness of the support on which it is deposited, aging of the reflector or fabrication imperfections. Under some conditions, in particular in terms of dimensions of these roughnesses which are not negligible compared to the wavelength of the photons, these roughnesses produce a local phenomenon of diffusion of the light which induces an uncontrolled variation of the angle of reflection of the photons and therefore an overall reduction of the guiding effect provided by the waveguide.